Modular stimulus applicator system and method

ABSTRACT

A modular stimulus applicator system and method are disclosed. The system includes a plurality of wirelessly controlled stimulus pods, anchored to a patient&#39;s body, and configured to deliver stimulus to the patient&#39;s body. The stimulus can be heat, vibration, or electrical stimulus, or any combination thereof. The stimulus pods are controlled by a control station that can include a user-interface through which the patient can control application of the stimulus.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.13/981,081 which was filed on Apr. 1, 2014, which was 371 U.S. nationalphase of international application PCT/US12/22252, filed Jan. 23, 2012,which claims the benefit of priority to U.S. Provisional PatentApplication No. 61/435,221, filed on Jan. 21, 2011, all of which arehereby incorporated by reference in their entirety.

STATEMENT OF GOVERNMENT INTEREST

The U.S. Government has a paid-up license in this invention and theright in limited circumstances to require the patent owner to licenseothers on reasonable terms as provided for by the terms of grants1R43CA099305-01A2, 2R44CA099305-02 and 2R44CA099305-03 awarded by theNational Institutes of Health.

TECHNICAL FIELD

The following disclosure relates generally to stimulus-based therapeuticdevices, systems, and methods. In particular, the disclosure relates tosystems and methods for applying heat, vibration, electrical, and otherstimulus to a patient's body for therapeutic purposes.

BACKGROUND

In 1965, Melzack and Wall described the physiologic mechanisms by whichstimulation of large diameter non-pain sensory nerves could reduce theamount of unpleasant activity carried by pain nerves. This landmarkobservation published in Science was termed the “gate control theory”and offered a model to describe the interactions between various typesof the sensory pathways in the peripheral and central nervous systems.The model described how non-painful sensory input such as mildelectrical stimulation could reduce or gate the amount of nociceptive(painful) input that reached the central nervous system.

The gate-control theory stimulated research that lead to the creation ofnew medical devices such as transcutaneous electrical nerve stimulators(TENS). In brief, TENS works by electrically “blocking” pain impulsescarried by peripheral nerves. Receptors to cold and heat are locatedjust below the surface of the skin. Heat receptors are activated througha temperature range of about 36° C. to 45° C. and cold receptors by atemperature range about 1-20° C. below the normal skin temperature of34° C. (Van Hees and Gybels, 1981). The stimuli are transmittedcentrally by thin poly-modal C nerve fibers. Activation of heatreceptors are also affected by the rate of rise of the heat stimuli(Yarnitsky, et al., 1992). Above 45° C. warm receptor dischargedecreases and nociceptive response increases producing the sensations ofpain and burning (Torebjork et al., 1984).

Activation of poly-modal thermal receptors causes significant painrelief in controlled experimental conditions. Kakigi and Watanabe (1996)demonstrated that warming and cooling of the skin in human volunteerscould significantly reduce the amount of reported pain and somatosensoryevoked potential activity induced by the noxious stimulation of a CO2laser. The authors offered that the effects seen could be from a centralinhibitory effect produced by the thermal stimulation. Similarinhibition of pain from thermal simulation was reported in a differentHuman experimental pain model (Ward et al., 1996). The study authors(Kakigi and Watanabe 1996 and Ward et al., 1996) proposed that thethermal analgesia was in part from a central inhibitory effect (gating)from stimulation of small thin C nerve fibers. This contrasts with TENSwhich produces at least part of its analgesia through gating brought onby activation of large diameter afferent nerve fibers.

A number of recent clinical studies strongly support the use of heat asan analgesic in patients who suffer from chronic pain and offerpotential mechanisms by which heat produces analgesia. Abeln et al.(2000) in a randomized controlled single-blinded study examined theeffect of low level topical heat in 76 subjects who suffered from lowback pain. Heat treatment was statistically more effective in relievingpain and improving the quality of sleep than that produced by placebo.

Weingand et al. (2001) examined the effects in a randomized, singleblinded, controlled trial of low level topical heat in a group of over200 subjects who suffered from low back pain and compared heat toplacebo heat, an oral analgesic placebo, and ibuprofen 1200 mg/day. Theauthors found heat treatment more effective than placebo and superior toibuprofen treatment in relieving pain and increasing physical functionas assessed by physical examination and the Roland Morris disabilityscale.

A separate group (Nadler at al, 2002) found similar results in aprospective single blinded randomized controlled trial of 371 subjectswho suffered from acute low back pain. The authors found that cutaneousheat treatment was more effective than oral ibuprofen 1200 mg/day,acetaminophen 4000 mg/day or oral and heat placebos in producing painrelief and improving physical function. The authors offered severalhypotheses for the mechanism(s) of action which includes increasedmuscle relaxation, connective tissue elasticity, blood flow, and tissuehealing potential provided through the low-level topical heat. Similarbeneficial effects of topical heat were show in patients who sufferedfrom dysmenorrhea (Akin et al., 2001), and temporomandibular joint painTMJ (Nelson et al., 1988).

A recent study used power Doppler ultrasound to evaluate the effects oftopical heat on muscle blood flow in Humans (Erasala et al., 2001).Subjects underwent 30 minutes of heating over their trapezius muscle andchanges in blood flow were examined at 18 different locations over themuscle. Vascularity increased 27% (p=0.25), 77% (p=0.03) and 104%(p=0.01) with 39, 40 or 42° C. temperature of the heating pad.Importantly increases in blood flow extended approximately 3 cm deepinto the muscle. The authors concluded that the increased blood flowlikely contributed to the analgesic and muscle relaxation properties ofthe topical heat. Similar increases in deep vascular blood flow werenoted using magnetic resonance thermometry in subjects treated with mildtopical heat by two separate groups (Mulkern et al., 1999, and Reid etal., 1999).

Recent studies demonstrating the analgesic effectiveness of heat andprovided potential mechanisms of action. The mechanisms include areduction of pain through a central nervous system interaction mediatedvia thin c-fibers (Kakigi and Watanabe, 1996, Ward et al. 1996),enhancement of superficial and deeper level blood flow (Erasala et al.,2001, Mulkern et al., 1999, Reid et al., 1999), or local effects on themuscle and connective tissue (Nadler et al., 2002, Akin et al. 2001).TENS is thought to act through inhibition of nociception by increasingendogenous opioids or by a neural inhibitory interaction of nociceptionvia large diameter fibers. It is likely that TENS and heat act partlythrough different mechanisms with the potential for enhanced or evensynergistic interactions. TENS is widely used and endorsed by the painmanagement guidelines of both the AHCPR and American Geriatric Society(Gloth 2001). However a significant number of patients fail to achieveadequate relief with TENS or fail within six months of startingtreatment (Fishbain et al., 1996).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an isometric view of a heat pod and anchor according toembodiments of the present disclosure.

FIG. 1B is an exploded view of a heat pod according to embodiments ofthe present disclosure.

FIG. 2 is an exploded view of an anchor according to embodiments of thepresent disclosure.

FIGS. 3A-3C illustrate various attachment means between a stimulus podand anchor according to embodiments of the present disclosure.

FIG. 4 shows various attachment means between a stimulus pod and anchoraccording to embodiments of the present disclosure.

FIG. 5A is an isometric view of a non-contact charging station accordingto embodiments of the present disclosure.

FIG. 5B is a partially exploded view of a charging and/or controlstation according to embodiments of the present disclosure.

FIG. 5C is an isometric view of a contact charging station according toembodiments of the present disclosure.

FIG. 6 is a partially schematic view of index stimulus pods and dummystimulus pods, and a control station according to several embodiments ofthe present disclosure.

FIG. 7A is a graph of distribution of preferred pod temperature.

FIG. 7B is a graph of comfort values for different temperatures.

FIG. 7C is a graph of thermal sensation values for differenttemperatures.

FIG. 7D is a graph of temperature “liking” values.

FIG. 8A is a flow diagram illustrating clinical trial procedures.

FIG. 8B is a graph comparing Iowa Pain Thermometer scales for differentPMS pain treatments.

FIG. 8C is a graph comparing Numerical Rating Scales for different PMSpain treatments.

FIG. 9A is a graph comparing Iowa Pain Thermometer scales for differentlower back pain treatments.

FIG. 9B is a graph comparing Numerical Rating Scales for different lowerback pain treatments.

DETAILED DESCRIPTION

The present disclosure is directed generally to apparatuses, devices andassociated methods for applying heat to various parts of the human bodyusing a series of modular pods. The pods can be controlled by a remotecontroller in the form of a computer (a desktop or a laptop computer),or a mobile device such as a mobile phone, tablet or MP3 player. Thepods can releasably attach to disposable rings that adhere to the bodyat various locations to which the patient desires to direct heattherapy.

Several details describing thermal and electrical principles are not setforth in the following description to avoid unnecessarily obscuringembodiments of the disclosure. Moreover, although the followingdisclosure sets forth several embodiments of the invention, otherembodiments can have different configurations, arrangements, and/orcomponents than those described herein without departing from the spiritor scope of the present disclosure. For example, other embodiments mayhave additional elements, or they may lack one or more of the elementsdescribed below with reference to FIGS. 1-6.

FIG. 1A is an illustration of a stimulus pod system 100 in accordancewith several embodiments of the present disclosure. The system 100 caninclude a stimulus pod 110 and an anchor 120. The stimulus pod 110 canbe approximately 1″ in diameter, and can be equipped to deliverdifferent stimuli to the patient's body, including heat, vibration, andelectricity. In some embodiments, the pods 110 can include sensors thatgather information and relay the information back to a control station.Throughout this disclosure the stimulus pods 110 are referred tointerchangeably as stimulus pods 110, pods 110, or other types of pods110 without loss of generality. The anchor 120 can have an adhesivesurface that can be applied to various locations on a patient's body, anaperture 122, and an attachment ring 124 that can engage the pod 110 tohold the pod 110 onto the patient's body. Additionally or alternatively,pods 110 can be kept in place by clothing, magnets, Velcro-typeapplicator, elastic bands, pocket-like holders, braces, or other type ofapplicators capable of holding the pod against the patient's skin. Thepod 110 can be a stimulus pod 110 that has a heating surface 150 thatcontacts the patient's body to deliver stimulus in a measured,deliberate pattern to relieve pain and discomfort in the patient's body.Several of the stimulus pods 110 can be used in concert at differentplaces on the patient's body.

The stimulus pods 110 can also be used to deliver medicine to a patientthrough electrophoresis or iontophoresis. Electrophoresis is the motionof dispersed particles relative to a fluid under the influence of aspatially uniform electric field. Electrophoresis is ultimately causedby the presence of a charged interface between the particle surface andthe surrounding fluid. Iontophoresis (a.k.a. Electromotive DrugAdministration (EMDA)) is a technique using a small electric charge todeliver a medicine or other chemical through the skin. It is basicallyan injection without the needle. The technical description of thisprocess is a non-invasive method of propelling high concentrations of acharged substance, normally a medication or bioactive agent,transdermally by repulsive electromotive force using a small electricalcharge applied to an iontophoretic chamber containing a similarlycharged active agent and its vehicle. One or two chambers are filledwith a solution containing an active ingredient and its solvent, alsocalled the vehicle. The positively charged chamber (anode) will repel apositively charged chemical, whereas the negatively charged chamber(cathode) will repel a negatively charged chemical into the skin.

FIG. 1B is an exploded view of a stimulus pod 110 in accordance withseveral embodiments of the present disclosure. The stimulus pod 110 caninclude a stimulus surface 150 that contacts patient's skin to deliverheat, mild electrical stimuli, vibration, and/or other stimuli to thepatient's body. The stimulus pod 110 can also include a battery 155, acircuit board 160, a charging coil 165, and several housing elements170. The battery 155 can power the stimulus surface and the circuitboard 160. The battery 155 can be a lithium polymer battery or anothersuitable battery type. The charging coil 180 can be configured toreceive power from a power source and deliver the power to the battery155. The stimulus pod 110 can include a wireless communication link 175through which the stimulus pod 110 receives instructions and/or sendsdata to and from a control station (described in greater detail below).The housing elements 170 can include an upper cover 170 a and a body 170b that enclose the internal components and provide a convenient handlingsurface. The stimulus pods 110 can include attachment means to attachthe stimulus pod 110 to the anchor 120. For example, the stimulus pod110 can have metal slugs 105 that can be magnetized and coupled to ametallic attachment ring 124 in the anchor 120 to hold the stimulus pod110 to the anchor 120. The slugs 105 can also be used for stimulusdelivery. In selected embodiments, the metal slugs 105 can be positionedon a top side of the stimulus pods 110 and can be used to interface witha charging station discussed in more detail below.

FIG. 2 shows an anchor 120 as assembled, and in an exploded view inaccordance with several embodiments of the present disclosure. Theanchor 120 can include an upper surface 130, an attachment ring 124, anadhesive layer 135, and a liner 140. The liner 140 can be removed toexpose the adhesive layer 135 before placing the anchor 120 on thepatient's body. The upper surface 130 is exposed to the ambientconditions and accordingly can be similar to a bandage or a woundcovering to provide a clean, water-resistant surface for the anchor 120.Beneath the upper surface 130, the attachment ring 124 can include ametallic ring such as a steel ring that corresponds to magnets 185 inthe stimulus pod 110. The ring 124 is held to the upper surface 130 bythe adhesive layer 135, which can have an adhesive on the upper side toadhere to the ring 124 and the upper surface 130, and on the lower sideto adhere to the liner 140. The materials can all be rigid enough tomaintain a proper shape, but flexible enough to substantially conform tothe patient's body. For example, the ring 124 can be segmented or thinto permit the anchor 120 to flex to some degree. Once the anchor 120 isin its place on the body, the stimulus pod 110 can be placed into theaperture 122 in the anchor and held in contact with the patient's bodyto deliver heat and/or other stimulants to the patient.

FIGS. 3A-3C illustrate several embodiments in accordance with thepresent disclosure including various attachment means between the anchor120 and the stimulus pod 110. In many applications, the stimulus fromthe stimulus pod 110 is best delivered to the patient's body with astimulus surface 150 directly contacting the patient's skin. The anchorcan take different forms to keep the stimulus surface 150 against thepatient's skin, some of which are shown using the cross-sectional viewsof FIGS. 3A-3C. FIG. 3A shows a stimulus pod 110 having a plug 152 athat extends slightly beyond the anchor 120. The plug 152 a can have astimulus surface 150 a with a flat profile. The attachment ring 124 canengage the stimulus pod 110 with sufficient force that the stimulussurface 150 a presses down onto the patient's skin to ensure sufficientcontact with the skin. FIG. 3B shows an alternative embodiment includinga plug 152 b with a stimulus surface 150 b that is convex. The slope ofthe convex stimulus surface 152 b can depend in part on the applicationand size of the stimulus pod 110. The convex stimulus surface 150 b canhave more surface area than the flat stimulus surface 150 a, providedthat the slope is not too extreme such that portions of the stimulussurface 150 b do not contact the patient's skin. FIG. 3C illustrates yetanother embodiment including a plug 152 c that similarly extends beyondthe anchor 120, and has a stimulus surface 150 c. In this embodiment,the stimulus surface 150 c has several small bumps or projections 240.The dimensions of the stimulus surface 150 c and the bumps 240 can bechosen to increase the surface area of the stimulus surface 150 c thatcontacts the patient's skin without creating void spaces or air pocketsbetween the bumps 240 that might reduce effective heat transfer ordelivery of other stimuli. In some embodiments, the projections 240 arenot discrete, but are continuous and/or sinusoidal.

FIG. 4 illustrates several embodiments of the present disclosure inwhich the attachment means between the anchor 120 a and the stimulus pod110 include various attaching mechanisms. FIG. 3A contains severalmagnified views of a region marked “A” which depicts the interfacebetween the anchor 120 a and the stimulus pod 110. In some embodiments,the anchor 120 a contains a metallic or magnetic ring 250 thatcorresponds to a magnet 185 in the stimulus pod 110. The magnetic forcebetween the ring 250 and the magnets 185 hold the stimulus pod 110 inplace relative to the anchor 120 a. In other embodiments, an anchor 120b can be held to the stimulus pod 110 by a mechanical fastener 255 suchas a snap, or other similar mechanical attachment means. In someembodiments, the attachment mechanism can operate along the sameprinciple as a plastic cap on a cardboard cup, such as a coffee cup andlid. Either the stimulus pod 110 or the anchor 120 b can contain aresilient recession and the other can contain a matching, resilientprojection that, when pressed together, mechanically hold the stimuluspod 110 in place on the anchor 120 b. In still other embodiments, ahook-and-loop fastener 260 can be used. Other embodiments use theinterior surface 265 of an anchor 120 d and a corresponding, resilientexterior surface 270 of a plug 152 d that can be pressed into theaperture 122 of the anchor 120 and snap into place. Yet anotherembodiment includes opposing threaded surfaces on an anchor 120 e and aplug 152 e such that the stimulus pod 110 can be screwed into the anchor120 with a stimulus surface 150 e protruding beyond the anchor 120 e toensure proper contact with the patient's skin. In other embodiments, ananchor 120 f can include a keyed aperture 122 having an irregularinterior surface 265, and a plug 152 f of the stimulus pod 110 caninclude a correspondingly irregular external surface 270 that can beplaced over the aperture 122 and rotated slightly with portions of theirregular exterior surface 270 engaging with the anchor 120 f to holdthe stimulus pod 110 in place.

Any of the attachment mechanisms provide a simple way for a patient toapply a stimulus pod 110 to their body. The stimulus pods 110 can beinterchangeable between anchors 120, and vice versa. A patient can use astimulus pod 110 until the battery is depleted, and then simply swap inanother stimulus pod 110 with a fresh battery. The attachment means canbe strong enough and the dimensions of the stimulus pod 110 can be smallenough that the stimulus pod 110 can be worn under the patient'sclothing easily. The placement of the anchors 120 can vary greatlyaccording to a predetermined diagnostic pattern or personal preference.In some embodiments, the stimulus pods 110 can be placed at an area ofdiscomfort, such as a painful lower back. Some research suggests thatplacing additional stimulus pods 110 at an area remote from a problemarea can also provide analgesic effects. For example, a patient may usea stimulus pod 110 at the lower back—where the pain is—but they can alsouse a secondary stimulus pod 110 near the shoulders or on the legs.Multiple stimulus pods 110 can be used in concert to produce anaggregate affect. As different areas of the human body have differentnerve densities, in certain areas two stimulus pads 110 placed near oneanother are perceived as a single, large stimulus pad 110. For example,the patient's back has much lower nerve density than the face, neck, orarms. Accordingly, the patient can use a pair of small stimulus pads 110(e.g., one or two inches in diameter) at the lower back spaced aboutthree or four inches apart and achieve the same sensory result as alarger stimulus pad covering the entire area. An unexpected benefit ofthis arrangement is that much less power is required to provide thestimulus in two small areas than would be required to stimulate theentire area.

FIGS. 5A and 5B illustrate a charging station 200 according to severalembodiments of the present disclosure. FIG. 5A shows a charging station200 including several sockets 205 shaped to receive a single stimuluspod 110. In the embodiment shown, the charging station 200 includes foursockets 205. Other configurations can have a different number of sockets205. FIG. 5B is a partially exploded view of the charging station, whichcan include a charging coil 210 and a circuit board 215 under eachsocket 205. The charging station 200 can also include an electricalconnector 220 that can be plugged into a standard electrical outlet orother power source to provide power to the charging station 200. Thecharging station 200 can detect when a stimulus pod 110 is seated in thesocket 205 through a wireless signal, a proximity sensor, or because thepods 110 depress a button in the sockets 205. When the stimulus pods 110are on the charging station 220, the corresponding circuit board 215 caninstruct the charging coil 210 to transmit power to the charging coil180 of the stimulus pod 110. In some embodiments, the stimulus pods 110can have an asymmetric shape that matches a corresponding, negativeshape in the sockets 205 to ensure proper alignment with the sockets205. The pods 110 can include a contact point that can be used forcharging the pods 110 or as control inputs for the pods 110. In anotherembodiment, the stimulus pods 110 can include contacts on a topside(e.g., on the upper cover 170 a) through which the pods 110 can exchangeelectrical power and communication signals when placed on the sockets205 with the upper cover 170 a face-down. Several details of theelectrical arrangement of the charging station 200, such as wires andother electrical connectors, have not been shown to avoid obscuringfeatures of the present disclosure.

The charging station 200 can include a light 225 that can indicate thatthe charging station 200 is transmitting power to a stimulus pod 110.When the battery 155 of the stimulus pod 110 is fully charged, thestimulus pod 110 can notify the charging station 200 which can thencease charging the battery 155 and change the light 225 to indicate thatthe battery 155 is fully charged and is ready for use. When there areseveral stimulus pods 110 having different power levels in differentsockets 205, the charging station 200 can charge the stimulus pods 110that have less than a full charge while not powering the stimulus pods110 that have a more full charge.

FIG. 5C shows a charging station 211 according to several embodiments ofthe present disclosure. The illustrated charging station 211 has twosockets 205 for receiving stimulus pods 110, but a charging station withjust one or more than two sockets 205 is also possible. The chargingstation 211 can be plugged into a standard electrical outlet using acord 212. Sockets 205 have socket connectors 214 that mate with podconnectors 209 when a pod is inserted into a socket. Sockets 205 canhave a notch 213 to accommodate an on/off switch 207 on the stimulus pod110. The notch 213 can also serve as a keying feature to assure properalignment of the socket connectors with the pod connectors 209.

FIG. 5C further shows the stimulus pods 110 having the pod connectors209 either on the lower surface of the pod (as shown in the upper viewof the stimulus pod 110) or on the upper surface of the pod (as shown inthe lower view of the stimulus pod 110). In some applications it may beadvantageous to have the pod connectors 209 on the upper surface of thestimulus pod, because that surface is away from the patient's skin; inconsequence, the connector contamination is less likely. The stimuluspod 110 can also have on/off switch 207. A simple push type on/offswitch is illustrated, but many other types of switches are alsopossible including, for example, a slide switch, an optical switch,touch sensor, etc. In use, the on/off switch is typically activatedafter the contact with the patient's skin has been established, becausethe patient's skin provides a minimum threshold temperature below whichthe stimulus pod 110 will not activate, which can also be a safetymechanism preventing an accidental discharging of the stimulus pod. Inaddition to its power on/off function, the on/off switch 207 can beconfigured to control a number of heat cycles and/or temperature of thestimulus pod 110. The stimulus pod 110 can also have a heat cycle switch206 to choose heat level like, for example, low, medium or high. Thecorresponding indicators 208A-C can light up in response to a particularheat cycle switch 206 setting. In the alternative, a single indicator208 capable of changing its color can be used to indicate low, medium orhigh temperature. A push type heat cycle switch 206 is illustrated inFIG. 5C, but other types of switch like, for example, slide switch,multi-pole throw switch, touch sensitive switch, etc. are also possible.

In several embodiments, the stimulus pods 110 can communicate with acontrol station 230, shown schematically in FIG. 5B through any acceptedwireless or wired protocol, including radio frequency (RF), infraredlight, laser light, visible light, acoustic energy, BLUETOOTH, WIFI, orother communication systems. Additionally, the signals can be sent andreceived through the patient's skin. In addition to providing acommunication path among the pods, sending and receiving signals throughthe patient's skin may be particularly well suited for determining adistance between the pods. The control station 230 can be a desktop orlaptop computer, a smartphone, for example an i-Phone, or other device.The control station 230 can be included with the charging station 200,and in some cases can share components such as a power source,circuitry, etc. The control station 230 can instruct one or morestimulus pods 110 to apply heat, electric stimuli, vibration, or otherstimulus or combination of stimulus in various patterns to the patient'sbody. In other embodiments the pods 110 include a button or series ofbuttons through which the pods 110 can be manually operated. Thepossible applications are many, and include various combinations of rampup operations, maximum intensity operations (e.g., maximum temperatureor maximum electrical current, etc.), ramp down operations, stimulussoak operations, and lockout period operations. The stimulus can beapplied from different stimulus pods 110 at different levels andpatterns. For example, a patient may place a stimulus pod 110 at theirupper back, their lower back, and near each of their shoulders or in adifferent arrangement. The control station 230 can vary the stimulusapplication at the various zones according to a predetermined pattern.If a smartphone or other device having a screen is used as a controlstation, the screen may display a graphical representation of patient'sbody with indication as to where to locate the pods 110 in a particularapplication. Furthermore, the screen may display a countdown timeinformation for all or some pods 110.

In several embodiments, the control station 230 can have informationregarding the location of the stimulus pods 110 on the patient's body,and can vary the stimulus pattern accordingly. In one embodiment, thestimulus pods 110 can be built with certain body positions in mind. Thestimulus pods 110 can carry body position labels to instruct the patientto apply the stimulus pods 110 according to the label. For example, in aset of four stimulus pods, two can be marked “shoulders,” a third can bemarked “lower back,” and a fourth can be marked “upper back.” In someembodiments, the anchors can communicate its location to the stimuluspod 110. The anchor 120 can include a passive identifier such as an RFIDtag or other simple, passive method of communicating with the stimuluspod 110. In this embodiment, the anchor 120 can remain in place evenwhen different stimulus pods 110 are swapped in and out of the anchor120. The stationary anchor 120 can accurately provide locationinformation to the control station 230 independent of which specificstimulus pod 110 occupies the anchor 120.

In other embodiments, the patient can inform the control station 230where the stimulus pods 110 are situated, and with this information thecontrol station 230 can apply the desired stimulus pattern to thestimulus pods 110. For example, the stimulus pods 110 can firesequentially, and the patient can indicate the location of the stimuluson a user interface. Through the user interface, the patient can alsooperate the system 100 and apply treatment. In one embodiment, a controlstation 230 that comprises a smart phone or a computer, a graphicdepiction of the patient's body can be shown and the patient canindicate to the control station 230 where the stimulus pods 110 arelocated. Alternatively, the patient can directly control the stimulusapplication through the stimulus pods 110 by moving a pointing devicealong the graphical depiction of their body to create a virtualstimulus-massage that the patient, or a healthcare professional,controls directly. In some cases the control station 230 can include atouch screen that the patient can touch to apply heat or other stimulusto various portions of their body (or to the body of another patient).

FIG. 6 depicts further embodiments of a stimulus delivery system 100according to the present disclosure. In some embodiments, the stimulusdelivery system 100 includes a control station 230, at least one indexpod 110 a, and several dummy pods 110 b. The relationship between theindex pod 110 a and the dummy pods 110 b can be similar to amaster/drone relationship. The index pod 110 a can include moresophisticated telemetry equipment than the dummy pods 110 b, and can actas an intermediary between the dummy pods 110 b and the control station230. The index pod 110 a may include stimulus components, such as aheating surface or vibration equipment, and can deliver stimulus justlike a dummy pod 110 b. Alternately, the index pod 110 a can be adedicated index pod 110 a with communication equipment, but withoutstimulus equipment.

In some embodiments, the index pod 110 a and control station 230 candiscern when two or more stimulus pods 110 (e.g., dummy pods 110 b orindex pods 110 a) are near enough to one another that they can work inaggregate. If the control station 230 knows where the stimulus pods 110are placed on the patient's body, the control station 230, through theindex pods 110 a, can vary the threshold distance between stimulus pods110 a, 110 b as a function of nerve density at different locations onthe body. For example, if the control station 230 discerns that two ormore dummy and/or index pods 110 a, 110 b are three inches apart and onthe lower back, the control station can operate the stimulus pods 110 a,110 b together to effectively cover the area between the stimulus pods110 a, 110 b as well as the area directly contacting the stimulus pods110 a, 110 b. By comparison, if stimulus pods 110 a, 110 b are threeinches apart, but are placed on a more sensitive area, such as thepatient's face or neck, the control station 230 can determine that theaggregate effect may not be perceived to reach the area between thestimulus pods 110 a, 110 b because of the greater nerve density. Thisinformation can be used when applying a treatment plan that calls forstimulus on a prescribed area. The control station can determine whetherthere is a stimulus pod 110 on or near the prescribed area, and if not,whether the aggregate effect from two or more stimulus pods 110 can beused to carry out the treatment plan, and can execute the plan throughthe pods 110.

Several clinical studies were performed to evaluate effectiveness of thestimulus pod system. Details of the clinical studies and the results areprovided below. FIGS. 7A-D show the results of a study that was designedto understand how to optimize heat levels, intermittency and heatdistribution to produce more effective analgesia (pain relief). FIGS.8A-C show comparison results between a ThermaCare heater and thestimulus pod system as in this invention treating the pre-menstrualsyndrom. FIGS. 9A-C show comparison results between the ThermaCareheater and the stimulus pod system as in this invention when treatinglower back pain.

Study of Characteristics of Thermal Analgesia in Human Subjects

A stimulus pod system for the clinical study was designed and built tooptimize heat levels, intermittency and distribution. The stimulus podsystem included a software controller, a set of instructions on a laptopcomputer and a hardware interface that connected a variety of stimuluspods to the laptop controller. A person skilled in the art would knowthat many types of controllers and interfaces could be used for themodular stimulus applicator system including, for example, off-shelfdedicated controllers and a software based controller on a smart phoneor a tablet computer connected through a wireless or wired interfaces tothe stimulus pod system. The software controller was used to controlthermal variables. These variables include:

maximum temperature (° C.) of the high heat cycle (T-max);

rate of temperature climb (Δ° C./seconds) for the initial heat cycle(T1-Ramp-up);

duration of T-max (seconds) (T-max time);

rate of temperature reduction (Δ° C./seconds) to the baseline soaktemperature (Ramp-down). There was no active cooling, so the Ramp-downtime was a passive variable;

minimum temperature (° C.) of the low heat cycle (T-soak);

duration of T-soak (seconds) (T-soak time);

rate of temperature climb (Δ° C./seconds) for the subsequent heat cycle(T2-Ramp-up);

wave forms of both the high heat (T-max) and low heat (T-soak) cycles (asquare wave form or a saw tooth pattern). The temperature differencebetween the peak and valley of the saw tooth heat waves wascontrollable;

time (in seconds) from the beginning of one ramp up period to thebeginning of the next ramp up period (Heat cycle); and

time (in minutes) of a number of sequential heat cycles (demand cycle).

The control laptop was connected via a USB port to a heating interfaceunit. This interface allowed controlling one to four stimulus pods. Thepods had electrical resistance pads with embedded thermistors, whichallowed for very tight control of temperature. The study initiallyutilized three sizes of stimulus pods: small (0.5×0.5 inches), medium(1×1 inches) and large (1.5×1.5 inches). The stimulus pods wereconnected to the heating interface unit with 8 ft long cables thatallowed test subjects to move about the testing station.

The protocol was initially tested on 10 in-house subjects. Afterwards, atotal of 23 outside subjects completed the entire initial protocol whichwas done in one 90 minute session. The results of the in-house testingwere similar to the formal trial results. Within the group of 23 testsubjects, 14 were females (61%) and 9 males (39%) with a mean age of 31years (range 17-59, standard deviation±9.9 years). The subjects weregiven explanation about the study procedure and study device. In aninitial subset of subjects, each subject tried three different sizes ofstimulus pods (small, medium, large) to determine what size waspreferred for the subsequent phases of the study. The midsize stimuluspod was strongly preferred, and was used for the subsequent studies. Insome instances, the subjects could not determine if the smallest pad waseven heating. Also, there was no preference among the subjects forheating a larger area of the body by using a larger size (1.5×1.5inches) stimulus pods.

Furthermore, a study was done to determine whether the subjectspreferred a temperature above that which can be produced by a ThermaCarepad. Clinical observation indicated that many people who use heat as atherapy prefer temperatures which are in fact hot enough to causehypertrophic changes of the underlying skin. These temperatures are mostcommonly obtained using electrical heating pads. Commercially availablechemical heating pads, e.g., ThermaCare, can provide temperature only upto 40° C. The subsequent clinical observations indicated that thistemperature limited the therapeutic effectiveness of chemical heatingpads.

Once a subject's preferred temperature profile was determined, thesubject was fitted with a variety of stimulus pods, and locations andthe preferences were recorded. It was observed that the subjects wereable to detect a difference in heat pulses of less than 1° C. Asexplained in more detail below, the subjects preferred a temperaturethat was significantly warmer (44.7° C.) than the 40° C. provided byThermaCare.

The initial testing was done to determine the preferred temperature ofthe stimulus pods. The heating started at 41° C. for two minutesduration and then gradually increased in the 0.5° C. increments up toeither a maximum temperature of 50° C. or until the subject felt thatthe pads were too hot. The initial ramp-up (T1-Ramp-up) was also variedand evaluated for the subject preference. FIG. 7A shows that thepreferred heating pad temperature was 44.6° C. (range 42-48° C.,standard deviation±1.4° C.). Only a few subjects preferred a temperaturegreater than 46 degrees. Furthermore, as shown in FIG. 7B, subjectsindicated that the perceived comfort of the heating pads graduallyincreased with the temperature up to approximately 45.5° C. Thereafter,the perceived comfort declined for most subjects. The comfort level canrange from 3, which signifies “very comfortable,” to −3, which signifies“very uncomfortable.” The vertical bars on the plot symbols indicateconfidence interval in all graphs.

The temperature preferences and ratings were quantified using a thermalsensation scale that progressed from “very cold,” “cold,” “slightlycool,” “neutral,” “slightly warm,” “warm,” “hot,” to “very hot.” Asshown in FIG. 7C, the subjects indicated that the pads felt increasinglywarmer up to about 47° C. In the graph of FIG. 7C, the thermal sensationis scales from 0 (temperature neutral) to 6 (very hot). For thetemperature above about 46° C., the temperature was rated as a “hot” or“very hot.” As shown in FIG. 7D, the subjects indicated a gradualincrease in “liking” of the temperature until about 46° C. The “liking”was on the scale of 0 (terrible) to 10 (wonderful). The temperaturerange from about 44° C. to about 46° C. was the closest to “wonderful.”Outside of the 44° C. to 46° C. range, the temperature “liking” wasfalling away from “wonderful.”

It was also observed that some subjects liked an additional pod placedon their body distant to the area that was painful. This is likely justa distraction effect, but it still increased the effectiveness of theheating pod that was placed over the body part in pain.

In summary, this study systematically evaluated properties of heat thatare likely to relate to thermal analgesia. The subjects preferredtemperatures that were significantly hotter than the 40° C., which canbe provided by chemical heat packs such as, for example, ThermaCare. Theactual or optimal temperature preferred by the subjects varied andapproached a bell shaped distribution. Initially, it was assumed thatthe small size heating pods (0.5×0.5 inches) or the large size heatingpods (1.5×1.5 inches) would be preferred by subjects. However, themedium size pads were the most preferred. It is possible that the smallpads were too small to optimally stimulate the cutaneous thermalreceptive fields. In many instances when subjects were asked how largeof an area was being stimulated both the medium and large pods produceda heated area that was similar in size. In most instances once the podswere removed, subjects continued to report that the skin still felt asif it was being heated. Furthermore, in several subjects with a painfularea of the body not being heated e.g., neck, reported that thisproximal unheated area “felt better” when a distant area e.g., low backwas heated.

The above clinical study demonstrated a “dose response” in the subjects.There is also a distinct fall-off as temperatures increase above 45-46°C. The distribution is relatively tight, and it provides little marginfor error with analgesic devices, such as chemical hot packs with poorlycontrolled or too low temperature. Furthermore, it is possible that heatpulses may provide more stimulation of the cutaneous receptors incomparison to a steady heat wave.

Study of Heat Treatment of Premenstrual Syndrome (PMS) Pain

FIGS. 8A-C illustrate the results of clinical studies of the stimuluspod system as applied for the treatment of PMS and dysmenorrhea(menstrual cramps felt during menstrual periods). PMS affects a largepercentage of women—more than 50 percent of all women who have amenstrual period. About 20% to 40% of women experience symptoms thatmake life difficult. Approximately 5 to 15 percent of these women havesevere pain that interferes with daily activities. Additionally, 2.5% to5% experience PMS that is debilitating. Heat is a well recognized selftreatment technique used to help relieve the cramps and the pains (back,abdominal and pelvic) associated with PMS. In spite of both empiricevidence and formal studies little is known about mechanisms or heatdoses that are effective for PMS relief. Recent studies demonstrate thatlow level heat can significantly reduce PMS pain, and can even reducethe amount of pain medications used to treat PMS.

The hypothesis of this study was that a high level pulsed heat would bemore effective than a low level continuous heat in relieving painassociated with PMS. The study compared analgesic effects of thestimulus pod system as in this invention with those of a commerciallyavailable ThermaCare® wrap. The stimulus pod system consisted of twoheating pads that can be set to a temperature selected by the individualsubject. The temperature range of the heater could be set between andincluding 42 to 47° C. The ThermaCare wrap is a commercial productavailable over the counter. The ThermaCare wrap is attached to the skinusing its own elastic wrap. ThermaCare heats at a steady 40° C.

All subjects met with a research assistant (RA) prior to the start ofthe study. The RA explained and demonstrated the heating devicesoperation, their purpose and the methods of the study. The subjects wererandomly assigned to one of two groups: the stimulus pod system or theThermaCare group. All subjects completed a brief questionnaire abouttheir pain. The study flow is illustrated in FIG. 8A.

Subjects rated their PMS pain level using Numeric Pain Scale and IowaPain Thermometer. Those subjects who were initially assigned to theThermaCare had the device placed over their area of greatest pain(anterior abdomen or lower back). ThermaCare devices were allowed towarm up at least 30 minutes before being placed on the subject. Subjectsrated their pain levels at baseline (time zero) and after 10, 20 and 30minutes. After the first treatment session there was a 30 minute washoutperiod.

Those subjects who were assigned to the stimulus pod system group wereshown the study device. The RA facilitated a run-in period in which thesubjects were able to gradually increase the temperature of the heatingpads starting at 42° C. up to a maximum of 47° C. Once the subjectsselected study temperature, the subjects wore the stimulus pod systemand provided pain assessments at baseline and after 10 minutes, 20minutes and 30 minutes. After completing the study subjects filled outan exit interview questionnaire and were paid for their participation.

FIG. 8B shows the results of the Iowa Pain Thermometer measurements forthe stimulus pod system and ThermaCare. The results indicatesignificantly greater decrease in Iowa Pain Thermometer scores frombaseline to 30 minutes when participants used the stimulus pod systemdevice in comparison with ThermaCare use. Similar differences were foundfrom the baseline to 10 minutes, and from the 20 to 30 minuteassessment. No significant differences were found in the reduction ofIowa Pain Thermometer scores in the 10 to 20 minutes assessment.

FIG. 8C shows the results of the Numeric Rating Scale. The reduction inNRC from baseline to 30 minutes was greater when using the stimulus podsystem. The subjects that used the stimulus pod system device alsoreported greater reduction of pain on the Numeric Rating Scale frombaseline to 10 minutes, and from 20 to 30 minutes. Similarly to the IowaPain Thermometer scores, no significant differences were found for thetwo devices in the pain reductino from 10 to 20 minutes.

In conclusion, both treatments produced significant reduction in pain inthe subjects suffering from PMS pain. When compared to ThermaCare, thestimulus pod system produced significantly higher pain relief. In theexit interviews, the subjects almost unanimously noted that they allpreferred the warmer temperatures from the stimulus pod system thanthose offered by the low level heat of the ThermaCare product. Manysubjects also explained that they very much liked the pulsing sensationprovided by the Heater device.

Study of Heat Treatment of Low Back Pain (LBP)

FIGS. 9A-C illustrate the results of the lower back pain study. Onethird of all Americans suffer from back pain at some point during agiven year. The estimated number of individuals in the United Statesthat suffer from chronic pain varies from 160 million on down, but isgenerally cited as being close to 50 million. The lower back pain costsemployers more than $60 billion a year in lost productivity. If the costof treatment is added to that number, then the cost is estimated atabout $100 billion a year. Men and women are equally affected by theback pain. The pain occurs most often to people between ages 30 and 50,due in part to the aging process, but also as a result of sedentary lifestyles with too little (sometimes punctuated by too much) exercise. Therisk of experiencing low back pain from disc disease or spinaldegeneration also increases with age. Back pain is the second mostcommon neurological ailment in the United States—only headache is morecommon.

Heat has long been a mainstay treatment for low back pain. A number ofrecent studies demonstrated that heat reduces low back pain, improvesfunction and may result in the use of fewer pain medications. In spiteof both empiric evidence and formal studies little is known aboutmechanisms or dose response data for heat induced LBP relief. Thehypothesis of this study was that a high level pulsed heat would be moreeffective than a low level continuous heat in relieving chronic low backpain.

The subjects used the stimulus pod system or ThermaCare as explainedabove in relation to the Study of Heat Treatment of PremenstrualSyndrome Pain. Those subjects who were randomized initially to thestimulus pod system group were shown the study device. The RAfacilitated a run in period in which the subject was able to graduallyincrease the temperature of the heating pads starting at 42° C. up to amaximum of 47° C. Once the study temperature was selected, subjects worethe device and provided pain assessments at baseline and after 10minutes, 20 minutes, and 30 minutes. After completing the study, allsubjects filled out an exit interview questionnaire and were paid $100for study participation.

As shown in FIG. 9A, subjects indicated significantly greater decreasein Iowa Pain Thermometer scores from the baseline to 30 minutes when thestimulus pod system was used. Similar conclusion applies to the timefrom the baseline to 10 minutes, and from the 20 to 30 minuteassessment. No significant differences were found between the devices inreduction of the IPT scores from 10 to 20 minutes.

FIG. 9B shows that the reduction of pain rating on the Numeric RatingScale from baseline to 30 minutes was also greater when using thestimulus pod system device. Similar to the Iowa Pain Thermometer scores,the subjects using the stimulus pod system also reported greaterreduction of pain on the Numeric Rating Scale from baseline to 10minutes, and from 20 to 30 minutes. No significant differences in thereduction of pain were found from 10 to 20 minutes.

In conclusion, both treatments (the stimulus pod system and ThermaCare)produced reduction in pain in the subjects who suffered from chronic lowback pain. The stimulus pod system produced significantly higher painrelief in comparison to ThermaCare. The higher heat provided by thestimulus pod system was associated with better and more profound painrelief. In the exit interviews, subjects almost unanimously noted thatthey all preferred the warmer temperatures from the stimulus pod systemthan that offered by the low level heat of the ThermaCare product. Manysubjects also stated that they very much liked the pulsing sensationprovided by the Heater device.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thespirit and scope of the various embodiments of the invention. Further,while various advantages associated with certain embodiments of theinvention have been described above in the context of those embodiments,other embodiments may also exhibit such advantages, and not allembodiments need necessarily exhibit such advantages to fall within thescope of the invention. Accordingly, the invention is not limited,except as by the appended claims.

1-6. (canceled)
 7. A therapeutic stimulus application system,comprising: a plurality of stimulus pods, individual stimulus podscomprising a battery, a first communication link, and a stimulusdelivery surface for application to selected portions of a human bodythrough which stimulus is applied to the portions of the human body; abase comprising a plurality of sockets configured to receive thestimulus pods, wherein the individual sockets comprise a powertransmission mechanism through which electrical power is transferred tothe battery of individual stimulus pods when the stimulus pods arepositioned in the socket; and a control station comprising a secondcommunication link configured to communicate with the firstcommunication link of individual stimulus pods, and an input devicethrough which input commands are received, wherein the control stationinstructs the stimulus pods to deliver the stimulus to the human bodyaccording to the input commands.
 8. The therapeutic heat applicationsystem of claim 7 wherein the control station and the base are part of asingle unit.
 9. The therapeutic heat application device of claim 7wherein individual stimulus pods comprise a disk-shaped deviceapproximately one inch in diameter, and wherein the stimulus pods areheld to the human body by an anchor.
 10. The therapeutic stimulusapplication system of claim 7 wherein the plurality of stimulus podscomprises at least one index stimulus pod and at least one dummystimulus pod, and wherein the index stimulus pod is configured tocommunicate between the dummy stimulus pod and the control station. 11.The therapeutic stimulus application system of claim 7 wherein thestimulus comprises heat, the system further comprising a thermal limitercomprising at least one temperature sensor, the thermal limiter being incommunication with the plurality of stimulus pods to instruct thestimulus pods to cease applying heat if the temperature sensor detects atemperature above a predetermined threshold temperature.
 12. Thetherapeutic stimulus application system of claim 11 wherein the thermallimiter comprises a thermal fuse that interrupts power to the stimulusdelivery surface if the temperature sensor detects a temperature abovethe predetermined threshold temperature.
 13. The therapeutic stimulusapplication system of claim 7 wherein the control station comprises aportable electronic device.
 14. The therapeutic stimulus applicationsystem of claim 7 wherein the power transmission mechanism comprises aninduction charger, and wherein the stimulus pods comprise an inductioncharge receiver that transfers energy from the induction charger to thebattery.
 15. The therapeutic stimulus application system of claim 7wherein the power transmission mechanism comprises a conductive charger,and wherein the stimulus pods comprise a jack for connection to theconductive charger.
 16. The therapeutic stimulus application system ofclaim 7, further comprising a memory for storing a sequence ofoperations for the stimulus pods.
 17. The therapeutic stimulusapplication system of claim 16 wherein the sequence of operationscomprises a combination of ramp up operations, maximum stimulusintensity operations, ramp down operations, stimulus soak operations,and lockout period operations.
 18. The therapeutic stimulus applicationsystem of claim 17 wherein: the ramp up operations comprise graduallyincreasing a temperature applied through the heating surface of thestimulus pods; the maximum stimulus intensity operations comprisemaintaining the stimulus at a predetermined maximum energy level; theramp down operations comprise gradually decreasing the stimulus; thestimulus soak operations comprise maintaining the stimulus at apredetermined soak stimulus level below the predetermined maximum energylevel; and wherein the lockout period operations comprise interruptingstimulus from the stimulus pods.
 19. The therapeutic stimulusapplication system of claim 17 wherein the input device receives aselection from between ramp up operations, maximum temperatureoperations, ramp down operations, temperature soak operations, andlockout period operations.
 20. The therapeutic stimulus applicationsystem of claim 17 wherein the stimulus pods execute the lockout periodfor a predetermined time interval in response to at least one of: atemperature exceeding a predetermined threshold temperature; an energydelivery level exceeding a predetermined threshold energy deliverylevel; and the stimulus applying stimulating the heating surface formore than a predetermined time threshold.
 21. A method, comprisinglocating a plurality of wireless stimulus pods relative to a patient'sbody; determining a treatment plan for stimulus delivery to thepatient's body through the stimulus pods, including at least one of aramp up operation, a ramp down operation, a stimulus soak operation, anda lockout period; and receiving operator input directing application ofthe stimulus to the plurality of stimulus pods, including a selectionfrom among the ramp up operation, the ramp down operation, the stimulussoak operation, and the lockout period; and instructing the stimuluspods to deliver the stimulus according to the treatment plan and theoperator input.
 22. The method of claim 21 wherein locating theplurality of wireless stimulus pods comprises wirelessly receiving anindication of location from the stimulus pods at a control station. 23.The method of claim 21 wherein receiving the operator input comprisesreceiving input through a user-interface of a control station, andwherein instructing the stimulus pods comprises instructing the stimuluspods from a control station to deliver the stimulus.
 24. The method ofclaim 21 wherein the stimulus comprises at least one of heat, vibration,and electrical stimulus.
 25. The method of claim 21, further comprisingdetecting an energy delivery level and comparing the energy deliverylevel to a predetermined threshold, wherein the lockout period isapplied if the energy delivery level exceeds the predeterminedthreshold.
 26. The method of claim 25 wherein the stimulus comprises atleast one of heat, vibration, and electrical stimulus, and wherein thepredetermined threshold includes a first threshold for heat, a secondthreshold for vibration, and a third threshold for electrical stimulus.27. The method of claim 25 wherein the stimulus is heat, the methodfurther comprising detecting a temperature of the stimulus pods, andwherein the lockout period continues until the temperature of thestimulus pods falls below a predetermined threshold temperature.
 28. Themethod of claim 21 wherein the lockout period is triggered after thestimulus has been continually applied for more than a predeterminedthreshold time.
 29. The method of claim 21, further comprisingpositioning the stimulus pods on the patient's body on or near a sourceof pain.
 30. The method of claim 21 wherein locating the wirelessstimulus pods and instructing the stimulus pods comprises communicatingfrom a base station to an index stimulus pod and from the index stimuluspod to at least one dummy stimulus pod.
 31. The method of claim 21wherein locating the plurality of wireless stimulus pods relative to thepatient's body comprises determining an area of the patient's bodydirectly contacted by a stimulus pod, and determining an area of effectnot directly contacted by the stimulus pod but within an effectiveregion of the stimulus pod.
 32. The method of claim 31 wherein the areaof effect varies according to positions on the patient's body.
 33. Themethod of claim 31 wherein the size of the area of effect is generallyinversely proportional to a nerve density of the patient's bodycontacting the stimulus pod.